642993920 has 36 divisors (see below), whose sum is σ = 1540174440. Its totient is φ = 257197056.

The previous prime is 642993919. The next prime is 642993931. The reversal of 642993920 is 29399246.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249890 + ... + 252449.

Almost surely, 2^642993920 is an apocalyptic number.

It is an amenable number.

642993920 is an abundant number, since it is smaller than the sum of its proper divisors (897180520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642993920 is an equidigital number, since it uses as much as digits as its factorization.

642993920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502360 (or 502346 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 44.

The square root of 642993920 is about 25357.3247800315. The cubic root of 642993920 is about 863.1155787515.

The spelling of 642993920 in words is "six hundred forty-two million, nine hundred ninety-three thousand, nine hundred twenty".